1. Field of the Invention
The invention relates to a direct fire or direct contact water heater.
2. Description of the Prior Art
U.S. Pat. Nos. 4,275,708; 4,753,220; 4,765,280; 4,773,390; 5,168,861; 5,305,735; 5,368,474; 5,479,913 disclose direct contact water heaters.